Fixed-wing aircraft typically include various flight control surfaces that enable adjustment and control of the aircraft's flight. For example, flaps mounted on trailing edges of wings modify the effective contour of the wings and, thus, modify the lift characteristics of the wings. In certain types of flap systems, an inboard flap includes a torque member that is used to move the flap between stowed and deployed positions. Typically, the torque member extends into the side of the fuselage, or into a wing fairing structure of the fuselage, and is coupled to a flap support mechanism that controls movement of the flap.
In many flap systems, the torque member is a tubular structure having a circular cross-sectional shape, commonly referred to as a torque tube. The torque tube is typically coupled to a structural member of the flap, such as an inboard rib. However, achieving appropriate structural and load-bearing performance can require a heavy torque tube and large and complex couplings that increase the weight and cost of the aircraft. Additionally, some flap systems utilize a failsafe torque tube that includes a dual torque tube design that further increases the cost, weight, and complexity of the aircraft.
Accordingly, those skilled in the art continue with research and development efforts in the field of aircraft wing flap actuation.